Do you run a diesel car – then you probably know that it can be run on veggie oil instead of diesel fuel. The only condition for veggie oil is that it has to be heated to at least 160F(71ºC). Mickey Sklar has designed a device that monitors three temperature sensors.

Veg monitor circuit can be used for:

• monitoring grease temperature level
• determining when to flip from diesel to veg
• detecting cold spots
• detecting clogged filters (rapid grease temperature drop)

Circuit is built around atmega169 which reads three thermistors where each temperature value increase is indicated by LED. You can analyse source code here… and let your car smell like pancakes

Temperature controller uses TMP37 temperature sensor from Analog Devices. As PIC 16F84 doesn’t have any analogue inputs there is an external ADC TLC549 used which converts temperature sensor readings in to serially transmitted digital data.

Temperature controller is also interfaced with four buttons( for setting parameters like alarm, set point) and LCD display where current temperature is displayed. Project is very well explained, with lots of helpful links that explain all the basics including understanding and flashing PIC microcontrollers.

IF you need good standalone IR decoder, you should consider this one. It’s hardware is really simple to build. All you need is to upload PIC program that are separate for for different IR standard and you can inspect IR code on 4x seven segment LED display.

Decoder is built around PIC16F84 microcontroller which drives LED displays and reads IR signal by using two IR receivers that are tuned for 36 and 38kHz carrier. You can download asm and hex files for analysing different IR protocols from here. Right now there are JVC, NEC, NRC-17 and RC-5 standards supported.

This is yet another IR remote signal analyser which can capture IR signals and display its waveform via PC software. This project started as a way to send IR remote control signals from a PC to control hi-fi equipment, etc. A front-end program written in Java will run on the PC and communicate with a PIC based circuit via the serial port. The PIC based circuit listens to commands on the serial port and sends out the IR signals.

The IR analyser is build around PIC16F876 microcontroller which drives one input along with standard LED indicator to show incoming IR signal. Another LED indicator lights when learning mode is on. And of course there is a IR transmitting LED which can send IR signals to desired remote equipment. IR analyser can understand commands via RS232 input or simply send received signals to PC front end programs. PIC program is written in pure ASM language and front end program is written in Java.

In some embedded projects you need to use DC motors and there is always what driver IC to use. Chris offers to try L298HN motor driver IC.

Chip is actually well known H-Bridge which allows to drive DC motor in both direction but also can variate it’s speed with PWM inputs. In this particular example project Motor driver IC is interfaced to PIC18F452 microcontroller. Microcontroller generates signals needed to drive motor to selected direction and speed. Only to integer variables need to be adjusted. Sample code is available for download. This might be a good resource for your next upcoming project.